+++ /dev/null
-dnl AMD K6 mpn_mul_1 -- mpn by limb multiply.
-dnl
-dnl K6: 6.25 cycles/limb.
-
-
-dnl Copyright (C) 1999, 2000 Free Software Foundation, Inc.
-dnl
-dnl This file is part of the GNU MP Library.
-dnl
-dnl The GNU MP Library is free software; you can redistribute it and/or
-dnl modify it under the terms of the GNU Lesser General Public License as
-dnl published by the Free Software Foundation; either version 2.1 of the
-dnl License, or (at your option) any later version.
-dnl
-dnl The GNU MP Library is distributed in the hope that it will be useful,
-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-dnl Lesser General Public License for more details.
-dnl
-dnl You should have received a copy of the GNU Lesser General Public
-dnl License along with the GNU MP Library; see the file COPYING.LIB. If
-dnl not, write to the Free Software Foundation, Inc., 59 Temple Place -
-dnl Suite 330, Boston, MA 02111-1307, USA.
-
-
-include(`../config.m4')
-
-
-C mp_limb_t mpn_mul_1 (mp_ptr dst, mp_srcptr src, mp_size_t size,
-C mp_limb_t multiplier);
-C mp_limb_t mpn_mul_1c (mp_ptr dst, mp_srcptr src, mp_size_t size,
-C mp_limb_t multiplier, mp_limb_t carry);
-C
-C Multiply src,size by mult and store the result in dst,size.
-C Return the carry limb from the top of the result.
-C
-C mpn_mul_1c() accepts an initial carry for the calculation, it's added into
-C the low limb of the result.
-
-defframe(PARAM_CARRY, 20)
-defframe(PARAM_MULTIPLIER,16)
-defframe(PARAM_SIZE, 12)
-defframe(PARAM_SRC, 8)
-defframe(PARAM_DST, 4)
-
-dnl minimum 5 because the unrolled code can't handle less
-deflit(UNROLL_THRESHOLD, 5)
-
- .text
- ALIGN(32)
-
-PROLOGUE(mpn_mul_1c)
- pushl %esi
-deflit(`FRAME',4)
- movl PARAM_CARRY, %esi
- jmp LF(mpn_mul_1,start_nc)
-EPILOGUE()
-
-
-PROLOGUE(mpn_mul_1)
- push %esi
-deflit(`FRAME',4)
- xorl %esi, %esi C initial carry
-
-L(start_nc):
- mov PARAM_SIZE, %ecx
- push %ebx
-FRAME_pushl()
-
- movl PARAM_SRC, %ebx
- push %edi
-FRAME_pushl()
-
- movl PARAM_DST, %edi
- pushl %ebp
-FRAME_pushl()
-
- cmpl $UNROLL_THRESHOLD, %ecx
- movl PARAM_MULTIPLIER, %ebp
-
- jae L(unroll)
-
-
- C code offset 0x22 here, close enough to aligned
-L(simple):
- C eax scratch
- C ebx src
- C ecx counter
- C edx scratch
- C esi carry
- C edi dst
- C ebp multiplier
- C
- C this loop 8 cycles/limb
-
- movl (%ebx), %eax
- addl $4, %ebx
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, (%edi)
- addl $4, %edi
-
- loop L(simple)
-
-
- popl %ebp
-
- popl %edi
- popl %ebx
-
- movl %esi, %eax
- popl %esi
-
- ret
-
-
-C -----------------------------------------------------------------------------
-C The code for each limb is 6 cycles, with instruction decoding being the
-C limiting factor. At 4 limbs/loop and 1 cycle/loop of overhead it's 6.25
-C cycles/limb in total.
-C
-C The secret ingredient to get 6.25 is to start the loop with the mul and
-C have the load/store pair at the end. Rotating the load/store to the top
-C is an 0.5 c/l slowdown. (Some address generation effect probably.)
-C
-C The whole unrolled loop fits nicely in exactly 80 bytes.
-
-
- ALIGN(16) C already aligned to 16 here actually
-L(unroll):
- movl (%ebx), %eax
- leal -16(%ebx,%ecx,4), %ebx
-
- leal -16(%edi,%ecx,4), %edi
- subl $4, %ecx
-
- negl %ecx
-
-
- ALIGN(16) C one byte nop for this alignment
-L(top):
- C eax scratch
- C ebx &src[size-4]
- C ecx counter
- C edx scratch
- C esi carry
- C edi &dst[size-4]
- C ebp multiplier
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, (%edi,%ecx,4)
- movl 4(%ebx,%ecx,4), %eax
-
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, 4(%edi,%ecx,4)
- movl 8(%ebx,%ecx,4), %eax
-
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, 8(%edi,%ecx,4)
- movl 12(%ebx,%ecx,4), %eax
-
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, 12(%edi,%ecx,4)
- movl 16(%ebx,%ecx,4), %eax
-
-
- addl $4, %ecx
- js L(top)
-
-
-
- C eax next src limb
- C ebx &src[size-4]
- C ecx 0 to 3 representing respectively 4 to 1 further limbs
- C edx
- C esi carry
- C edi &dst[size-4]
-
- testb $2, %cl
- jnz L(finish_not_two)
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, (%edi,%ecx,4)
- movl 4(%ebx,%ecx,4), %eax
-
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, 4(%edi,%ecx,4)
- movl 8(%ebx,%ecx,4), %eax
-
- addl $2, %ecx
-L(finish_not_two):
-
-
- testb $1, %cl
- jnz L(finish_not_one)
-
- mull %ebp
-
- addl %esi, %eax
- movl $0, %esi
-
- adcl %edx, %esi
-
- movl %eax, 8(%edi)
- movl 12(%ebx), %eax
-L(finish_not_one):
-
-
- mull %ebp
-
- addl %esi, %eax
- popl %ebp
-
- adcl $0, %edx
-
- movl %eax, 12(%edi)
- popl %edi
-
- popl %ebx
- movl %edx, %eax
-
- popl %esi
-
- ret
-
-EPILOGUE()
projects / ghc-hetmet.git / blobdiff